INTRODUCTION

 EU has banned AGP-s (antibiotic growth promoters) in 2006 and researches has been carried out to find alternatives to control and prevent colonization of pathogen bacteria e.g. Salmonellas in the intestines modulating gut microbiota [Ribeiro et al, 2007]. Broilers produced in EU, must be free of Salmonellas since 2003. Salmonella infantis infection of broiler flocks and contamination of chicken meat came to the front and became almost exclusive. Beneficial effect of FWGE has been verified in Hungarian poultry production among others with the production parameters, immune reactions, mycoplasmosis and coccidiosis of broilers [Kósa et al, 2003, Stipkovits et al, 2004] production level and vaccination reactions with parent flocks of table egg layers [Kósa,E., Bajcsy.E., 2008] and histo-morphology of intestinal mucosa with broilers [Ózsvári et al, 2010].

 MATERIAL AND METHODS 

In two fully separated and climatized compartments each of them 14 m2 , 85 (group No I, experimental group) 85 (Group No II, control group) Ross 308 day old broilers originated from Salmonella free parent stock have been settled. Before settling floor, walls and all equipment including feeders, drinkers, door, etc. of the premises have been thoroughly cleaned first mechanically and by high pressure water secondly. After drying up of the premises all of the surfaces and equipment have been disinfected by 200 ml/m2 of 1% Virocid solution with high pressure spray. After complete drying up floor of the premises has been bedded by 10 cm thickness with heat treated, chopped straw closed into plastic sacks at the producer. Each compartment has been equipped by 3 small drinkers till the end of 2nd week and 2 bell drinkers till the end of rearing. 

In the first second weeks broilers were fed from the chicken boxes placed on the litter, and after 2 of 1,5 m long trough feeders have been placed in the compartments. Microclimate of the premises has been fitted by the usual broiler technology and controlled automatically. 1 hour light and 23 hours dark period have been used as lighting program with 20 lux. Both of the experimental and control flocks have been fed by a commercial broiler starter feed till the 14th day and grower feed till the end of rearing to the 42nd day, ad libitum. Starter feed of the experimental group have been completed by 3 g/kg, grower feed by 2 g/kg of FWGE. Feed of the control group did not contain FWGE. Each broilers of experimental and control groups has been orally infected by culture of live Salmonella infantis containing 10 000 000 bacteria/individual dose on the 4th day of rearing. Both groups has been vaccinated by coarse spray against ND and IB by Nobilis Vaccine Ma5+Clone 30 on the 1st day, against IBD by drinking with Nobilis Gumboro D78 vaccine on the 21st day and against ND by coarse spray with Nobilis vaccine Clone 30 on the 28th day. Environmental samples were taken by agar sausage method for Salmonella investigation before settling of birds from the surfaces of compartments, and from the covering papers of chicken boxes by the regulation of home veterinary authority180/2009.(XII.29.) FVM, based on Commission regulation (EC) No.1003/2005. Bloodsamples (10/groups) were taken by puncturing from cubital vein for determining of humoral antibody level of ND and IB on the 14th day, and determining of ND, IB, IBD humoral antibody level on the 28th day, finally ND, IB and IBD humoral antibody level on the 42nd day. 

Antibodies of ND have been tested by HI, IB by ELISA, IBD by VN. Cloaca tampon samples (10/groups) were taken on the 5, 6, 7, 9, 10, 15, 17, 22, 23, 29th day of rearing for Salmonella cultivation by enrichment method. Cecal samples were taken from 5 sacrificed birds/ group on the 35th and 37th day of rearing. Cecum has been removed after double ligation of the organ at the ileum avoiding contamination of its content. Drinking water samples, 1 l were taken in both compartments for Salmonellas before settling of flocks from the water supplying tap by the hygienic rule of sampling. Feed samples, 1 kg were taken for presence of Salmonellas from the starter feed on the 1st day of rearing and from the grower feed 16th and 30th day of the rearing with the experimental and control flock. Mortality has been noticed and the cause of it has been diagnosed. RESULTS Environmental samples a) 32 agar sausage and 11 drag swab samples taken from the surfaces of the two compartments proved to be negative for Salmonellas as well as the 500 g of bedding material (chopped straw). b) 5x5 g of covering papers spoiled by droppings (meconium) proved also to be negative for Salmonellas in the bacteriological investigation.Mortality In the group fed by FWGE supplementation died 5 birds (5.9 %) because of omphalitis,1, mechanical suffocation 1, polyserositis 1, pneumonia 2 birds. On the group fed without FWGE supplementation died 4 birds (4,7%), because of omphalitis 1, pericarditis 1, polyserositis 1, and pneumonia 1 broiler.

(Table 1) Beneficial effect of FWGE on the IB ELISA titres can be seen in t he Table 2, which proves that the titres on the 28th day (28 days after vaccination) 820% and on the 42nd day (42 days after vaccination) 180% higher antibody titres. (Table 2) As far as the ND HI titres are concerned as result of two vaccinations (1st day, 28th day) titres of blood samples taken on the 42nd day proved to be 100% higher with the FWGE + (Table 3) group compared to the controls and all samples proved to be positive. CONCLUSIONS Bacteriological investigation of cloaca swabs proves, that FWGE in the feed did not influence neither of dynamics nor intensity shedding of Salmonella infantis, but it can be stated, that while the cloaca-swabs became negative on the 23rd day of rearing (19 days after infection) cecal content proved to be positive even on the 37th day, so the flock remained salmonella positive in spite of negative tampon-results. Humoral immune response after vaccination has been positively influenced by FWGE in case of IBD vaccination till the 28th, in case of IB and ND till the 42nd day of rearing (slaughtering time). On the basis of the results of our study the conclusion may be drawn that FWGE has no positive effect in prevention of Salmonella infantis infection, but increases the immune responses after vaccination in broilers remarkably.